"Our belief and our philosophy is that the best testbed is space itself," said Chris Voorhees, who is Planetary Resources' vice president of spacecraft development, in a Google Hangout on Wednesday.

The Arkyd-3 satellites are about 30 cm long and 10 wide, and will be a test for larger Akryd-100 scouts set to be launched into low-Earth orbit to hunt for asteroids in 2015.

These larger satellites will look both for precious metals to return to Earth, but also for liquid water which could be used to enable astronauts to live on other planets and moons, both as drinking water but also as material to develop fuel and radiation shields.

Currently it costs around $10,000 to launch a liter of water into space, Planetary Resources said. While the cost of mining asteroids is enormous, future proliferation of exploration missions might make it feasible.

Other companies including Deep Space Industries and government space agencies are also planning on launching missions to scope out the possibility of landing on, or mining, asteroids in the relatively near future.